SC15 & SC16 - Dynamic Equilibria, Calculations Involving Volumes of Gases / Chemical Cells and Fuel Cells ✓

Their root hair cells

Root hair cells can only absorb mineral ions that are dissolved in water

• Nitrogen • Potassium • Phosphorus

A Nitrogenous (Nitrogen-rich) fertiliser and a source of soluble nitrogen compounds

• Ammonium is created through the Haber process. • Then some ammonia is reacted with oxygen to give nitric acid and oxygen. • This nitric acid is reacted with some ammonium solution. • This creates ammonium nitrate: • NH3 (g) + 2O2 (g) → HNO3 (aq) + H2O (l) • NH3 (aq) + HNO3 (aq) →NH4NO3 (aq)

• Hydrogen from natural gas • Nitrogen from the air

• scale of production - small • starting materials - ammonia solution and dilute sulfuric acid • stages - titration followed by crystallisation • type of process - batch process • maintenance -apparatus must be cleaned regularly - difficult to automate

• scale of production - large • starting materials - raw materials for making ammonia and sulfuric acid • stages - several stages • type of process - continuous • maintenance - only stopped rarely to maintain and clean equipment

• Sulfur and air are reacted to form sulfur trioxide • Sulfur trioxide is reacted with water to from Sulfuric acid

• Equilibrium shifts in the endothermic direction • Rate of attainment increased as the particles have more energy causing more frequent collisions. • (All are opposite if temperature is decreased)

• Equilibrium favors the side with fewer molecules • Rate of attainment is increased as the same amount of particles in a smaller space causes more frequent collisions • (Opposite if pressure is decreased)

• Equilibrium shifts towards the products side. • Rate of attaimment is increased as there are more particles in the same space and so there are more frequent collisions • (Opposite if concentration is decreased)

• Position of equilibrium is unaffected as it effects both sides equally • Rate of attainment is increased as the catalyst increases the rate of reaction without being used up

• Lightning. • An electric arc was created between two electrodes causing nitrogen to react with oxygen in the air forming nitrogen monoxide. • This was then further reacted with oxygen to form nitrogen dioxide and then dissolved in water to form nitric acid

• It was inefficient only producing a yield of 4% nitric acid • It cost lots as it took up huge amounts of electricity

The Ostwald process: • Ammonia + Oxygen ⇌ Nitrogen monoxide + Water • Nitrogen Monoxide + Oxygen ⇌ Nitrogen dioxide • Nitrogen Dioxide + Oxygen + Water → Nitric Acid

• Availability of raw materials and energy supplies • Rate of reaction and equilibrium position • Atom economy, yield and usefulness of the by-products

220° and 4atm with a hot platinum catalyst (Ammonia to Nitrogen monoxide is exothermic and there are more molecules on the right)

• Two different metals each dipped in a solution of one of their own salts • A salt (or ion) bridge to allow the ions to pass from one solution to another and complete the circuit

• Metals that have a greater difference in reactivity will create a larger potential difference. • This will also create a greater current as there are more electrons flowing past one point over a given time.

One of its reactants have been completely used up and so there are no more elctrons flowing past

A collection of cells

They are made out of reactants that can be reformed when electricity passes through them.

Hydrogen and Oxygen